Manufacture of superheater units.



O. K. LASSITER. MANUFAGTUBBOFSUPERHEATERUNITS.

APPLICATION FILED DEC. 2, 1913.

Patented Mar. 17, 1914.

V 2 sums-511mm 1.

INV ENTOR I 0. K. LASSITER. MANUFACTURE OF SUPERH EATER UNITS.

- APPLICATION FILED DEC. 2, 191a. 1,090,551. Patented Mar. 17, 1914 I 2 SHEETS-SHEET 2.

V FIG. 5: Z .9 1

WITNESS INVENTOR UNITED COLUMBUS K. LASSITER, OF RICHMOND, VIRGINIA.

struction whereby superheater units of such.

character may be readily and inexpensively -1 5 manufactured, and which will render available, as constituents thereof, drop forged or hydraulic pressed return bends, and to produce a superheater unit, as. an article'of manufacture, which shall be. of greater strength, durability, and effectiveness in service, than those of the ordinary construe 1 tioinj hy greasonfiof having its parts solidly and securely connected together, and fully exempt from liability to leakage attheir junctions.

The improvementclaimed is hereinafter fully set forth. p

In the accompanying drawings: Figure l is a view in elevation, of a superheater unit comanufactured under my invention; Fig.2,

a longitudinal section, on anenlarged scale, through. an end portion thereof;'Fig. 3, a view, in perspective, of a return bend :body;

..Fig. 4:, a similar view of a return bend cap; Fig. 5, a view similar to Fig. 2, showing a modified form of return bend; Fig. 6, a longitudinal section through the same, on the line "all of Fig. 6; and, Fig. 7 a transverse section, on the line Z) Z) of Fig. 5.

' As ordinarily constructed, superheater units of the class to which my invention relates are composed of parallel lines of seamless steel pipes and cast steel return bends,

' the ends of the lines of pipe being'connected by tapping or threading theminto the return bends. When so connected, leaks are frequently developed at the joints, after the units have been put inservice, these being due to imperfectly made or deteriorated joints, or to strains exerted on the units in removing-them from the boiler tubes. The cast steel return bends are also often found to be defective by reason of the presence of sand holes or other imperfections,necessi- Specification of Letters Patent.

Original application filed June 5, 1913, Serial No. 771,352. Divided and 1913. Serial No. 804,197.

MANUFACTURE or SUPERHEATER UNITS.

Patented Mar. 17, 1914. this application filed December 2,

heaters, are, under my invention, effectively eliminated.

Referring first to Figs. 1 to 4 inclusive of the drawings, for the practise of my invention,I provide a plurality of pipes, 1, Iof proper length and diameter, and return 5 bends for the connection of the ends of two jparallel lines of said pipes. The return bends, which are formed either by drop forging or by hydraulic pressure, are, as I shown, of sectional construction, each return bend comprising a hollow body section, 2, which is continuously open at one end, in the form of a flattened ellipse, and is turned, at its opposite end, into two cylindrical open ended projections, disposed side by side, and matching with, that is to say, substantially corresponding in diameter, and in thickness of metal, with the ends of the pipes to be connected, and a dished cap or cover section, 3, the form of which, at its open end, is a ellipse which corresponds with that surrounding the open end of the body section, as indicated in Figs. 3 and 4. The connection of'the two lines of pipe is effected by electrically welding the ends of the cylindrical projections of a body section, 2, of a return bend, to the corresponding ends of the two lines of pipe, and thereafter similarly welding a cap section, 3, to the opposite end of the body section. By reason of the correspondence, in transverse section, and consequent matching of the ends of the'pipes, body section, and cap, as above described, which is a novel and characteristic feature of my invention, there is no projection of metal beyondthe abutting surfaces to be welded, at any of the several welds, and therefore the welding, operation may be quickly and'economically effected by the ap:

plication of an alternating electric current and pressure, preferably that of air, acting on'one of-the members being welded, while the other is held stationary. This would not be practicable if metal projected beyond the surfaces to be welded. The two lines of pipe and the return bend are united by the above operation so as to form a solid, :and, for practical purposes, an integral structure, which presents no joints and is thereby exempt from liability to leakage, and is not subject to the loosening strains by which the ordinary threaded connections are deteriorated and rendered unfit for efficient service.

Figs 5v to 7 inclusive illustrate a structural modification of the return bend, which, in this case, is provided with removable plugs for affording access, if desired, to the interior of the pipe lines. The body section, 2, is of similar form to that before described, and a cap section, 3, is provided, which, instead of being cupped or dished, corresponds in tranverse section, throughout its length, to the open end portion of the body section, and its outer end, which is "plane, is provided with two openings, which are threaded, in line axially with the openings' of the body section, to receive removable plugs, 5, which are cupped or hollowed interiorly, as shown, to prevent them from being burned out by the action of the high heat to which they are subjected. Squared projections, 5, are formed on the plugs, for the application of a wrench in screwing them into and out of position. The pipe lines, 1, body section, 2, and cap section, 3, are electrically welded together, as in the instance first described. By removing the plugs, a reamer may be inserted, for the purpose of truing out the end portions of the pipes.

when performed by the resistance electric welding process, a flash or inwardly pro- 'jecting ring of metal is formed at the joints of the body section and pipe lines, the' presence of which would ordinarily so materially obstruct the bores of the pipes as to render them unfit for service ina superheater unit. The opposite end of the body section being, as shown, either entirely open I or closed by removable plugs, the flash, when so large as to be objectionable, can be readily and quickly removed by the insertion and rotation of a reamer, which clearing operation is efl'ectedbefore the ca is welded to the body section, and inasm'udh as the inside transverse sectional area of the completed return bend is materially greater than that of'the pipe lines, the reduction thereof by the flash formed at the joint of the body section and cap is inappreciable.

I claim as my invention and desire to secure by Letters Patent:

The improvement in the manufacture of superheater units which consists in forming a return bend body and a return bend cap, in separate sections having matching end surfaces, electrically welding each of the lines of pipe to a matching surface on one end of the return bend body, removing inward projections of metal at the welds by the application of a cutting tool, and thereafter electrically welding the cap section to the matching surface of the opposite end of the return bend body section.

COLUMBUS K. LASSITER.

Witnesses:

J. SNOWDEN BELL,

EDWARD A. WRIGHT. 

